6 research outputs found
Recommended from our members
Critical heat flux & two phase hydraulic investigation of a 16-rod simulation of a BWR fuel assembly
The combined effects of local power distribution and grid spacers on CHF were experimentally evaluated using an electrically heated 16 rod bundle simulation of a typical BWR fuel assembly. The single and two-phase hydraulic behavior of the test assembly was also evaluated. Data were obtained over a range of pressures (1000-1500 psia), mass velocities (0.5 x 10{sup 6} - 2.0 x 10{sup 6} lb/hr ft{sup 2}), and bundle-average exit qualities (0 - .40). CHF consistently occurred upstream of the last grid spacer indicating that the grid spacer improved coolant mixing downstream of it. CHF results compared well with other rod bundle CHF data available in the literature. Rod bundle two-phase pressure losses were accurately predicted via the COBRA code using the Homogeneous two-phase model in conjunction with empirically established single-phase hydraulic correlations for the bundle components
Recommended from our members
PNL-17: EBR-II INSTRUMENTED SUBASSEMBLY TEST. INTERIM REPORT.
Effect of Dissolved Oxygen on Redox Method for Measurement of Mass Transfer Coefficients
Recommended from our members
Thermal hydraulic analysis of the Pacific Northwest Laboratory fusion- fission hybrid reactor concept
Recommended from our members
Turbulet flow in a model nuclear fuel rod bundle containing partial flow blockages
Local velocity and turbulence intensity measurements were obtained with a laser Doppler anemometer near flow blockages in an unheated 7 x 7 rod bundle. Sleeve blockages were positioned on the center nine rods to create area reductions of 70 and 90 percent in the center four subchannels of the bundle. Experimental results indicated that severe flow disturbances existed downstream from the blockage clusters and showed that only minor disturbances can be expected upstream from the blockages. Recirculation zones for both 70 and 90 percent blockages were detected downstream from the blockage clusters and persisted for approximately three to five subchannel hydraulic diameters depending on blockage severity. The experimental velocity results obtained with blockage clusters located midway between grid spacers were successfully predicted using the COBRA computer program